Mode switching method applied to variable-speed control moment gyroscope

Abstract

The invention discloses a mode switching method applied to a variable-speed control moment gyroscope, which defines multiple working modes of the control moment gyroscope and switching logic between behaviors and modes of the moment gyroscope in the modes, and can realize uncontrolled, moment control and backup reaction wheel functions of the moment gyroscope. The moment gyroscope can be effectively applied to satellite attitude control.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite attitude and orbit control, and particularly relates to a method for mode switching of a variable-speed control moment gyroscope. Background Technique

[0002] A variable-speed control moment gyroscope (CMG) is a component used for satellite attitude control, which consists of a low-speed frame and a high-speed rotor. The high-speed rotor can achieve torque output through changes in speed, and the low-speed frame realizes torque output by rotating the frame axis. Since the high-speed component achieves torque output through rotor acceleration and deceleration, the speed change is smooth and the torque output is small, which is suitable for small angular velocity maneuvers; the torque output by the low-speed frame axis directly acts on the satellite body through the frame axis, and a larger control torque can be obtained. Reasonable working mode planning can enable it to switch reasonably between torque control, backup reaction wheels, and ground remote control functions according to the actual working conditions of the satellite, realizing the effective application of the variable-speed control moment gyroscope.

[0003] Currently, there are few mode switching methods applied to control moment gyroscopes, and more research focuses on the dynamic control of control moment gyroscopes. CN116880525A proposes a combined attitude maneuver control method for a flywheel and three control moment gyroscopes. Taking the apex of the flywheel angular momentum vector as the maneuver starting point, it searches for the maximum available angular momentum motion space inside the momentum body of the control moment gyroscope group, and inversely calculates the bias speed required for flywheel compensation and the corresponding initial frame angle of the control moment gyroscope group. According to the angular momentum motion space and torque output ability of the control moment gyroscope group, the control moment gyroscope group is connected to the closed loop for attitude control, but it does not classify the working modes of the control moment gyroscope. CN118145017A proposes a long-term sun-pointing control method for an inclined sailboard satellite based on three control moment gyroscopes. This method calculates the attitude control three-axis command torque according to the determined sun-pointing attitude, designs the command speeds of the three control moment gyroscopes based on the attitude control three-axis command torque, and realizes the long-term sun-pointing control of the inclined sailboard satellite, which can achieve sun-pointing for sailboards installed at any inclined angle, but does not involve the mode switching method of the control moment gyroscope. Summary of the Invention

[0004] In view of the actual application of the variable-speed control moment gyroscope on the satellite, the present invention proposes a mode switching method for the variable-speed control moment gyroscope, which clarifies the specific behaviors of the moment gyroscope in various working modes and the switching logic between working modes, and realizes the effective application of the moment gyroscope in satellite attitude control.

[0005] The technical solution of the present invention is: a mode switching method applied to a variable-speed control moment gyroscope, and the following 9 working modes are designed: Mode 1 Uncontrolled Mode, Mode 2 Startup Mode, Mode 3 CMG Mode, Mode 4 Recovery Mode, Mode 5 Backup Reaction Wheel Mode, Mode 6 Command Reaction Wheel Mode, Mode 7 Ground Takeover Mode, Mode 8 In-orbit Mode, and Mode 9 Fixed Angle Holding Mode;

[0006] The said Mode 1 Uncontrolled Mode: the high-speed rotor speed is 0 rpm, and the low-speed frame is fixed at 0°;

[0007] The said Mode 2 Startup Mode: the low-speed frame is fixed at 0°, and when the telemetry low-speed frame angle of the moment gyroscope is less than the low-speed frame angle control deviation If the high-speed rotor speed of the moment gyroscope is less than the operating speed When Use a fixed step size to increase the rotor speed to the operating speed;

[0008] The said Mode 3 CMG Mode: the low-speed frame angular velocity is controlled by commands, and the high-speed rotor maintains the speed;

[0009] The said Mode 4 Recovery Mode: the high-speed rotor speed command is 0 rpm. After the rotor speed is 0 rpm and maintained for a period of time, the low-speed frame angle is restored to 0°;

[0010] The said Mode 5 Backup Reaction Wheel Mode: the high-speed rotor receives the reaction wheel control command;

[0011] The said Mode 6 Command Reaction Wheel Mode: the high-speed rotor receives the reaction wheel control command, and the low-speed frame reaches the command position;

[0012] The said Mode 7 Ground Takeover Mode: both the high-speed rotor and the low-speed frame receive the ground single-machine command. If there is no command, the previous command is maintained;

[0013] The said Mode 8 In-orbit Mode: the low-speed frame is locked, and the high-speed rotor speed is set to 0 rpm;

[0014] The said Mode 9 Fixed Angle Holding Mode: the low-speed frame reaches the command position and maintains the frame angle.

[0015] Furthermore, when the current mode is Mode 8 In-orbit Mode, after the satellite is separated from the rocket, it switches to Mode 1 Uncontrolled Mode;

[0016] When the current mode is Mode 1 Uncontrolled Mode, when the satellite-rocket separation signal is not separated, it switches to Mode 8 In-orbit Mode;

[0017] When the current mode is Mode 1 Uncontrolled Mode, when the satellite working mode is a high-speed maneuvering mode and all CMG availability indicators are available, it switches to Mode 2 Startup Mode.

[0018] Further, when the current mode is the mode two startup mode, when all CMGs satisfy that the difference between the telemetry speed of the high-speed rotor and the target speed is less than the high-speed rotor speed error within consecutive cycles and the frame angle is less than the low-speed frame angle control deviation , switch to the mode three CMG mode;

[0019] When the current mode is the mode two startup mode, when any one of the available flags of any CMG is unavailable, any reaction wheel is unavailable, or the satellite working mode needs to switch out of the fast maneuvering mode, all CMGs simultaneously switch to the mode four recovery mode.

[0020] Further, when the current mode is the mode three CMG mode, when any one of the available flags of any CMG is unavailable, any reaction wheel is unavailable, or the satellite working mode needs to switch out of the fast maneuvering mode within consecutive cycles, all CMGs simultaneously switch to the mode four recovery mode;

[0021] When the current mode is the mode three CMG mode, when any single instance satisfies that the angular velocity of the satellite body is greater than the maximum angular velocity of the satellite body or any reaction wheel speed exceeds the limit, all CMGs simultaneously switch to the mode four recovery mode.

[0022] Further, when the current mode is the mode four recovery mode, when all satisfy within consecutive cycles that the commanded speed of the high-speed rotor is less than the high-speed rotor speed error and the CMG is available, the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation , switch to the mode one uncontrolled mode;

[0023] Among them, when the CMG is unavailable, it is default that the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation .

[0024] Further, when the current mode is the mode one uncontrolled mode, when all satisfy the following conditions: Condition one, there is exactly one unavailable reaction wheel; Condition two, if the available flag of the CMG is available, set the low-speed frame fixed angle holding angle of the CMG to the low-speed frame desired angle , and set the current CMG to the fixed angle holding mode, set other CMGs to the uncontrolled mode; switch to the mode nine fixed angle holding mode.

[0025] Further, when the current mode is the mode nine fixed angle holding mode, when all satisfy within consecutive cycles that the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation , the available flag of the CMG is available, and the telemetry speed of the high-speed rotor is less than the high-speed rotor speed error , switch to the mode five backup reaction wheel mode.

[0026] Further, when the current mode is the mode five backup reaction wheel mode or the mode nine fixed angle holding mode, and any of the continuous multiple attitude control cycles satisfies that the reaction wheels are all available or the CMG availability flag is unavailable, switch to the mode four recovery mode.

[0027] The beneficial effects of the present invention are as follows: A mode switching method applied to a variable speed control moment gyro is provided. This method clarifies various working modes of the control moment gyro, the behaviors of the moment gyro in the modes, and the switching logic between the modes, can realize the functions of uncontrolled, torque control and backup reaction wheel of the moment gyro, and can effectively apply the moment gyro in satellite attitude control. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the mode switching process applied to a variable speed control moment gyro. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will be further described below with reference to the drawings.

[0030] Since the rocket launch process is accompanied by severe vibrations and the CMG low-speed frame bearing is a vulnerable component, it is necessary to design a working mode to lock the low-speed frame shaft in a clamped state before the satellite and rocket are separated, so as to reduce the impact of rocket vibrations on the CMG. During the on-orbit stage of the satellite, considering that the CMG is a hot standby component for the reaction wheel, in order to avoid the deflection of its frame shaft with the change of the satellite attitude, thus affecting the overall satellite stability control, it is necessary to design a working mode as the usage mode during the CMG hot standby process. When the satellite needs to use the CMG for high maneuvering tasks, it is necessary to design a working mode to increase the speed of the CMG high-speed component, so as to prepare for the torque output control of the low-speed frame shaft. When any reaction wheel of the satellite fails and the CMG needs to be used as a backup reaction wheel for small torque output, it is necessary to design a working mode to transfer the high-speed rotor of the CMG to an appropriate angle for variable speed control of the high-speed rotor component. Considering the above application scenarios of the CMG during the on-orbit process of the satellite, design the working modes of the CMG and the corresponding mode switching conditions.

[0031] In the mode switching method, a total of 9 working modes are designed, which are specifically as follows:

[0032] (1) Uncontrolled mode: The high-speed rotor speed is 0 rpm, and the low-speed frame is fixed at 0°.

[0033] (2) Start-up mode: The low-speed frame is fixed at 0°. When the telemetry low-speed frame angle of the moment gyro is less than the low-speed frame angle control deviation (the error between the actual low-speed frame angle and the target angle (0°) of the current moment gyro), if the high-speed rotor speed of the moment gyro is less than the operating speed If a desired rotational speed to be used is required, the rotational speed of the rotor is increased to the operating speed using a fixed step size. ; ( Modifiable);

[0034] (3) CMG mode: The angular velocity of the low-speed frame is controlled by commands, and the high-speed rotor maintains its rotational speed.

[0035] (4) Recovery mode: The rotational speed command of the high-speed rotor is 0 rpm. After the rotational speed of the rotor is 0 rpm and maintained for a period of time, the angle of the low-speed frame is restored to 0°.

[0036] (5) Backup reaction wheel mode: The high-speed rotor receives reaction wheel control commands.

[0037] (6) Command reaction wheel mode: The high-speed rotor receives reaction wheel control commands, and the low-speed frame moves to the commanded position.

[0038] (7) Ground takeover mode: Both the high-speed rotor and the low-speed frame receive ground single-machine commands. If there are no commands, the commands from the previous cycle are maintained.

[0039] (8) In-orbit mode: The low-speed frame is locked, and the rotational speed of the high-speed rotor is set to 0 rpm.

[0040] (9) Fixed-angle holding mode: The low-speed frame moves to the commanded position and maintains the frame angle.

[0041] The switching logic between working modes is shown in Table 1 below:

[0042] Table 1

[0043]

[0044]

[0045]

[0046]

[0047] The above working modes organize the working modes of the CMG from before entering orbit to in orbit, enabling the momentum gyro to achieve the momentum output function when the satellite needs to quickly maneuver in a certain direction; enabling it to realize the function of the backup reaction wheel when a single reaction wheel fails; and also enabling it to achieve the momentum control function according to ground commands. The switching logic of the working modes realizes the automated application scenarios of the CMG under different working conditions of the satellite, providing a control strategy for the in-orbit application of the CMG.

[0048] Example 1

[0049] Step 1: When the satellite and the launch vehicle are not separated, the momentum gyro is in the in-orbit mode. After the separation of the satellite and the launch vehicle, it switches to the uncontrolled mode.

[0050] Step 2: After entering the uncontrolled mode, the momentum gyroscope can enter the torque control or reaction wheel working state. When the satellite enters the high-speed maneuvering working mode and other conditions are met, the momentum gyroscope enters the torque control state. First, it enters the startup mode, the gyroscope frame remains at 0°, and the rotor speed is increased to a fixed value. When the rotor speed reaches the requirement, it enters the CMG mode. At this time, the rotor speed is maintained, and the gyroscope frame rotates according to the frame axis angular velocity command to achieve the high-speed maneuvering of the satellite around a certain axis of the alert body.

[0051] After entering the uncontrolled mode, if any of the satellite reaction wheels is unavailable, it enters the backup reaction wheel mode. First, a momentum gyroscope frame is fixed at a certain angle in the required direction of the torque. After meeting the requirements, it switches to the backup reaction wheel mode. At this time, the high-speed rotor receives the reaction wheel speed command and functions as a backup reaction wheel.

[0052] In the CMG mode, if the satellite needs to exit the high-speed maneuvering working mode, or conditions such as abnormal reaction wheels are met, it switches to the recovery mode.

[0053] In the backup reaction wheel mode, if all reaction wheels are available or the momentum gyroscope is unavailable, it switches to the recovery mode. In the recovery mode, the rotor speed is set to 0 rpm. After the speed reaches 0 rpm, the frame angle returns to 0°, and then the momentum gyroscope enters the uncontrolled mode.

[0054] Step 3: All program control modes other than the orbit injection mode can be switched to the reaction wheel mode or the ground takeover mode through ground commands. In the command reaction wheel mode, the frame angle is determined by the ground command, and the rotor receives the reaction wheel command and functions as a custom reaction wheel. In the ground takeover mode, both the frame and the rotor are controlled by the ground command and function as a custom function.

[0055] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A mode switching method for a variable speed controlled torque gyro, characterized in that: The following 9 working modes are designed: Mode 1 uncontrolled mode, Mode 2 start mode, Mode 3 CMG mode, Mode 4 recovery mode, Mode 5 backup reaction wheel mode, Mode 6 command reaction wheel mode, Mode 7 ground takeover mode, Mode 8 orbit insertion mode and Mode 9 fixed angle holding mode; The first mode is the uncontrolled mode: the high-speed rotor speed is 0 rpm, and the low-speed frame fixed angle is maintained at 0°; Mode 2 start mode: The low-speed frame fixed angle is maintained at 0°, when the moment gyro telemetry low-speed frame angle is less than the low-speed frame angle control deviation If the torque gyro high-speed rotor speed is less than the operating speed , then use a fixed step size to increase the rotor speed to the operating speed ; Mode 3 CMG mode: the low-speed frame angular velocity is controlled by instructions, and the high-speed rotor maintains the speed; Mode 4 recovery mode: the high-speed rotor speed command is 0 rpm, the rotor speed is 0 rpm and maintained for a period of time, and then the low-speed frame angle is restored to 0°; The fifth mode is a backup reaction wheel mode: the high-speed rotor receives the reaction wheel control command; The mode six command reaction wheel mode: the high-speed rotor receives the reaction wheel control command, and the low-speed frame moves to the command position; Mode 7 ground takeover mode: both the high-speed rotor and the low-speed frame receive ground single-machine instructions, and if there is no instruction, the last beat instruction is maintained; Mode 8: In orbit mode: the low-speed frame is locked and the high-speed rotor speed is set to 0 rpm; Mode nine fixed angle holding mode: low speed frame to command position and maintain the frame angle.

2. A mode switching method for a variable speed controlled torque gyro according to claim 1, characterized in that: The current mode is Mode 8 orbit insertion mode. When the satellite separates from the rocket, it switches to Mode 1 uncontrolled mode. The current mode is Mode 1 Uncontrolled Mode. When the satellite-rocket separation signal is not separated, it switches to Mode 8 Orbit Insertion Mode. The current mode is Mode 1 Uncontrolled Mode. When the satellite working mode is high-speed maneuvering mode and the CMG available flags are all available, it enters Mode 2 Startup Mode.

3. The mode switching method for a variable speed controlled torque gyro according to claim 1, characterized in that: The current mode is Mode 2 startup mode. When all CMGs in a continuous cycle meet the condition that the difference between the high-speed rotor telemetry speed and the target speed is less than the high-speed rotor speed error, And the frame angle is less than the low speed frame angle control deviation When the 3rd mode is switched to CMG mode; The current mode is Mode 2 startup mode. When any CMG available mark is unavailable, any reaction wheel is unavailable, or the satellite working mode needs to switch out of the rapid maneuvering mode, all CMGs simultaneously switch into Mode 4 recovery mode.

4. The mode switching method for a variable speed controlled torque gyro according to claim 1, characterized in that: The current mode is mode 3 CMG mode. When any CMG available flag is unavailable, any reaction wheel is unavailable, or the satellite working mode needs to be switched out of the rapid maneuvering mode within a continuous period, all CMGs simultaneously switch into mode 4 recovery mode; The current mode is mode 3 CMG mode. When any single angular velocity of the star is greater than the maximum angular velocity of the star Or when the speed of any reaction wheel exceeds the limit, all CMGs simultaneously switch to Mode 4 recovery mode.

5. The mode switching method for a variable speed controlled torque gyro according to claim 1, characterized in that: The current mode is mode 4 recovery mode. When the high-speed rotor command speed is less than the high-speed rotor speed error in all consecutive cycles, When CMG is available, the difference between the telemetry frame angle and the target frame angle is less than the low speed frame angle control deviation When the switch mode is 1, the control mode is not available; When CMG is not available, the default is to ensure that the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation. .

6. The mode switching method for a variable speed controlled torque gyro according to claim 1, characterized in that: The current mode is mode 1 uncontrolled mode, when all the following conditions are met: Condition 1, one and only one reaction wheel is unavailable; Condition 2, if the CMG available flag is available, set the CMG low-speed frame fixed angle holding angle to the low-speed frame expected angle , and set the current CMG to fixed angle holding mode, and set other CMGs to no control mode; cut into mode nine fixed angle holding mode.

7. The mode switching method for a variable speed controlled torque gyro according to claim 1, characterized in that: The current mode is mode nine fixed angle holding mode. When the difference between the telemetry frame angle and the target frame angle is less than the low-speed frame angle control deviation in all consecutive cycles, , CMG available mark is available and the high-speed rotor telemetry speed is less than the high-speed rotor speed error , switch to Mode Five Backup Reaction Wheel Mode.

8. The mode switching method for a variable speed controlled torque gyro according to claim 1, characterized in that: The current mode is mode five backup reaction wheel mode or mode nine fixed angle holding mode. When any of the reaction wheels are available or the CMG available mark is unavailable for multiple consecutive attitude control cycles, the mode four recovery mode is entered.

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